
We did already get the first trailer, that's a step in the right direction, but Rockstar is releasing Max Payne 3 at the end of May... and apparently they do not normally release two big games in the same year, so that may be a step back. October is usually the month that GTA games are released, with the exception being GTA IV (which was orginally scheduled for October, but delayed,) this could be a good sign. Also, the next next generation consoles are purported to be released in Fall of 2013, which means if GTA V was held back until next year, they would either be cutting the life of the game short since new consoles would be released, or they might actually be making this game for the new consoles... but that's less likely since it appears the game is largely complete already (judging by the trailer.)
In my opinion, it makes sense that it will be released October of this year, I imagine that they are holding off on releasing too much information until early June, after Max Payne gets released. I doubt they want to cannibalize any of their products, so this seems logical to me. This would give Rockstar a good 5 months to whet our appetites with trailers and promotion.
I'll be crossing my fingers!